Digging a foundation in Rocky Soil areas????

[smullen]

Have any of you dug a foundation in an area thats extreamly rocky???

I've bought a small lot (real small) in a somewhat private lake are in Southern Missouri....

The place is on several hundred acres around a lake thats busted up into small lots that you buy and do what you will on; Be it Camp in a tent, pull in an RV, build a little shack, or a nice house...  Whatever... Out of a hundred or so lots there are only like 10 or so people that live there year round...  The rest are Summers, weekends, holidays, etc...


I want to build a medium sized cabin, maybe 1200sq feet... Something that we can use for the weekends and summer vacation now and maybe move into when we retire in about 10 years or so...

I was looking at all the work other members here have done and I saw some nice pics of the foundation that Mike and Katie had done...



Which made me wonder, have any of you had to dig a foundation in an areas thats really rocky???

I'm wondering how deep should I really go???

I would like a decent enough space to run plumbing, duct work and whatever under there and maybe small storage for some boxes if it'll stay dry...


Looking though the photos of everyones work is really inspiring...  You guys make stuff look too easy...

I can't wait to start on building a cabin...  In reality, it'll be months before I even attempt to break ground... I need to figure out exactly what/how I want to build it, budget for it and start making it happen..

[glenn kangiser]

What you do for a foundation could depend on what you want to do with it - freeze depths, soil conditions in your area, and other things.  You could even go to a post and pier foundation and eliminate much of the digging.

Welcome to the forum.

[Amanda_931]

Do not use a manual auger, either one- or two-person.  If it hits a serious rock, the auger part can stop, the handles take off--fast.  I was in pain for a week or so when an air ratchet did this, really would have hated to have something the size and power of an auger take off on me.

On the other hand, tractor mounted augers are a different story.  A big old 12" auger will do the job for you--either holes for pier and post, or continuous.  In the latter case you bore your holes in a zig-zag pattern.

Ditch Witches may be available for rent in your area with teeth especially suited for rocky soil.  They are here  They work pretty well, although getting a hole wide enough for a foundation might be a trick, a couple of lines, taking care to give yourself an escape route.

Post-hole diggers are pretty nice for removing soil you've already loosened with a digging stick (6 feet long cast iron jobs) or possibly taking out the middle from two or three lines of Ditch-Witch digging or tractor mounted auger.

Or if your backhoe guys are more reliable than mine, you could hire it done.

I've used all four of those methods here--let someone else run the ditch witch, hired the backhoe guy, etc.  Tractor auger, backhoe, ditch witch, digging sticks and/or a big crowbar.

Next project is tiny, so I think we'll go with the digging stick method.  Don't have to rent anything, don't have to put the auger back on the tractor--it's a bit too large for that tractor anyway, so it makes it really awkward two-person job to use.

[Chateau Prideaux]

Do not use a manual auger, either one- or two-person.  If it hits a serious rock, the auger part can stop, the handles take off--fast.  I was in pain for a week or so when an air ratchet did this, really would have hated to have something the size and power of an auger take off on me.

I have to second that. My dad and I rented a one person auger years back for digging fence holes. This was primarily sand and clay, easy stuff for the digger, but every so ofter it would hit a root. The auger stops and the handle starts... right into the ribs.

not much fun... especially after a 100+ holes.

As for rocky soils, I'm in the Texas Hill Country, which is nothing if not rocky. I borrowed a friend's jackhammer to bust some rocks just to put in batter boards and square some corners. Afterwards we decided we'll rent a power auger (walk behind type unit) for drilling the 20 or so piers.

As I look back over the last 3 years that I've had the property, I've found that using the right tool is worth the price. e.g. 3 weekends of hand labor where a couple hours with a bobcat would have done the job. It's a matter of how much your time and health is worth.

I guess the first that you need to decide is what type of foundation you'd like to use. The plans here support pier/beam and slab options. If it's relatively level, try for the slab, if your dealing with a slope, consider the pier/beam.

Due to slope, rocks and the desire to do as much myself (I'm stubborn as hell too) I opted for the pier/beam as it requires much less digging and concrete.

This website also helped provide the confidence that if 1-2 folks can sort it out, so can I.

Good Luck!